Thermal gelation of brown trout crude myofibrils and myofibrillar proteinsfrom white and red muscles

Heat-induced gelation properties of brown trout crude myofibrils and of myo fibrillar proteins (salt soluble) from white and red muscles were analysed by thermal scanning rheometry. Rheological characteristics of myofibrillar protein were similar to those of myofibrils, regardless of the muscle type. For both myofibrils and myofibrillar protein, stronger gels were observed at low pH values (5.6 vs. 6.0) and low ionic strength (0.2 M vs. 0.6 M KCl) . Interaction of myofibrillar proteins and that of myofibrils occurred at l ower temperatures in white muscle (starting at 20 degreesC) than in red mus cle. Gels observed after gradual heating to 80 degreesC were equally strong and elastic for both muscle types.